Yep. I'm considered an expert in self defense by some. In my seminars and classes I teach that everything can be a weapon. This is a teaching of the Chinese martial arts--ever see what Jackie Chan uses for weapons in his movies? An airplane is a weapon if you force it to be flown into a building. In my mind it is then a so-called "WMD" if it causes mass destruction.
The whole WMD definition is a political construct, not a linguistic one. Not being a political animal, but being a linguist, I look at the definition as being ridiculous in real life, where common sense is actually used.
So what's wrong with this picture? In 1995 the AUM terrorists used sarin gas, labeled a WMD by the politicians, to kill just 12 people. (I was almost caught up in a second attack the next day, not commonly reported in the American media because no one was killed.) However, terrorists force airplanes to be flown into buildings and kill multitudes and cause massive destruction--but that is not called an attack by a WMD. (And it is patently obvious that they were in control of the airplanes themselves, since they trained to fly.)